At noon today, students, faculty and administrators will gather in Tercentenary Theatre to reflect upon the events of Sept. 11 and its ramifications one year later.

Today’s ceremony will resemble the University-wide vigil attended by over 3,000 one year ago: University President Lawrence H. Summers will deliver the main address, followed by readings and music representing different religions.

This ceremony comes after months of preparation, beginning with the formation of an ad hoc committee under the United Ministries last spring.

While the logistics are similar to those of last year’s Sept. 11 ceremony, the tone will be noticeably different.

“Last year we were still absorbing the shock. Now we are reflecting on what it means and who we will become,” said Chaplain of Harvard College Mark D.W. Edington.

In addition to shaking the country’s sense of security, the terrorist attacks have forced a reexamination of American values, Summers said in an interview yesterday.

“I think it has been a reminder to a new generation that the values of our community are things that are bitterly opposed by some and are things that cannot be taken for granted,” Summers said.

In the face of these difficult questions, Summers said, he hopes the ceremony will provide some guidance.

The ceremony will be non-denominational, drawing on many religious traditions.

Taha B.H. Abdul-Basser, a graduate student adviser to the Harvard Islamic Society, will be one of three speakers to speak before Summers. Swami Tyagananda, president of United Ministry at Harvard, and Bernard Steinberg, executive director of Hillel, will also address the crowd.

At last year’s Sept. 11 vigil, Abdul-Basser spoke about the “dignity and integrity” of the Islamic tradition and said he plans to give a similar talk today.

But he said that after a year in which Muslims have repeatedly faced discrimination, the message is even more significant.

“My message may go beyond merely condemning the attacks to try to address things that have taken place between then and now and perhaps more importantly, things that have yet to take place,” he said.

A handful of students will read religious passages addressing hope and remembrance.

Matthew M. Mulder ’05, a Christian student who is a member of the Harvard-Radcliffe Christian Fellowship, said last night that he had not yet decided on a verse but would probably choose something from Revelations or Second Corinthians.